Sealed compressor

ABSTRACT

The present invention includes an electric component ( 331 ), a compression component ( 327 ), a sealed container ( 301 ), a suction pipe ( 324 ) and a discharge passage ( 405, 425   a   , 425, 470, 473 ). The compression component includes a crankshaft ( 343, 709 ), an oil feeding mechanism ( 368, 431, 433, 434, 708, 712, 713 ), an oil feeding passage ( 440, 714 ), and a scattering suppressing section ( 355, 455, 458, 461, 610, 616, 619, 706, 716 ). The scattering suppressing section suppresses the lubricating oil from being scattered from an opening of the oil feeding passage.

TECHNICAL FIELD

The present invention relates to a sealed compressor. In particular, the present invention relates to a lubricating structure of slide portions of the sealed compressor.

BACKGROUND ART

Conventionally, there is known a lubricating structure of a sealed compressor, in which lubricating oil is scattered from an upper end of a crankshaft to an entire of an interior of a sealed container (see, e.g., Patent Literature 1). This lubricating structure is is configured such that an electric component and a compression component actuated by the crankshaft rotated by the electric component are accommodated into a sealed container, and the lubricating oil suctioned up by utilizing a rotation of the crankshaft from a storage section of the lubricating oil which is formed in a bottom portion of the sealed container is scattered from the upper end of the crankshaft. The scattered lubricating oil lubricates slide portions of members of the electric component, the crankshaft, and the compression component. Especially, in this lubricating structure, there is provided an oil feeding hole which guides the lubricating oil scattered to an inner peripheral portion of a piston of the compression component, to slide portions of an outer peripheral surface of the piston and an inner peripheral surface of a cylinder. This can ensure that the lubricating oil is fed to the slide portions of the piston and of the cylinder, during a low-speed rotation.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese-Laid Open Patent Application     Publication No. 2009-203862

SUMMARY OF INVENTION Technical Problem

However, in the above stated conventional configuration, when the lubricating oil is scattered from the upper end of the crankshaft to the inner space of the sealed container, it is heated by high-temperature members of the compression component or the like. The lubricating oil which has raised its temperature is suctioned up to the upper end of the crankshaft and scattered again. Thus, the high-temperature lubricating oil is applied onto a discharge pipe, a cylinder head or the like, in which a refrigerant gas flows. The refrigerant gas is heated by the discharge pipe, the cylinder head, or the like which has raised their temperatures. Since the high-temperature refrigerant gas has a great specific volume, the amount of the refrigerant gas discharged from a compression chamber is reduced, which results in a reduced volumetric efficiency of the sealed compressor.

In some cases, the scattered lubricating oil is vaporized and suctioned into the compression chamber of the cylinder. Because of this, an internal volume of the compression chamber is reduced, and the amount of the refrigerant gas suctioned into the compression chamber is reduced. Therefore, the amount of the refrigerant gas discharged from the compression chamber is reduced, which results in a reduced volumetric efficiency of the sealed compressor.

Also, the refrigerant gas is heated by the scattered lubricating oil, and raises its temperature. Since the amount of the refrigerant gas suctioned into the compression chamber is reduced, the volumetric efficiency of the sealed compressor is reduced.

Since the lubricating oil receives heat and a pressure in the interior of the sealed compressor, the lubricating oil is more likely to be degraded (deteriorated). Also, the high-temperature lubricating oil may degrade members made of organic substances in the interior of the sealed compressor. Due to the degradation of the lubricating oil and the members, the sealed compressor becomes incapable of performing its function or fails, and hence a life of the sealed compressor is reduced.

The present invention has been made to solve the above mentioned problem, and an object of the present invention is to provide a sealed compressor which is capable of suppressing a reduction of its volumetric efficiency and a reduction of its life.

Solution to Problem

According to an aspect of the present invention, a sealed compressor comprises an electric component; a compression component actuated by the electric component; and a sealed container which accommodates the electric component and the compression component and stores lubricating oil in a bottom portion thereof; a suction pipe for guiding a refrigerant gas suctioned into and compressed by the compression component to an inner space of the sealed container; and a discharge passage for guiding the refrigerant gas compressed by the compression component, from the compression component to outside of the sealed container; wherein the compression component includes: a crankshaft including a main shaft rotated by the electric component and an eccentric shaft which is eccentric with the main shaft; an oil feeding mechanism provided in the main shaft to feed the lubricating oil stored in the bottom portion of the sealed container to slide portions of the compression component; an oil feeding passage provided in the eccentric shaft, communicated with the oil feeding mechanism and having an opening in a surface of the eccentric shaft; and a scattering suppressing section for suppressing the lubricating oil from being scattered from the opening of the oil feeding passage.

Advantageous Effects of Invention

The present invention has the above described configuration, and has advantages that it is possible to provide a sealed compressor capable of suppressing a reduction of its volumetric efficiency and a reduction of its life.

The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a longitudinal sectional view showing a sealed compressor according to Embodiment 2 of the present invention.

FIG. 2 is a cross-sectional (transverse-sectional) view showing an internal configuration of the sealed compressor of FIG. 1.

FIG. 3 is a schematic view showing a refrigeration system including the sealed compressor of FIG. 1.

FIG. 4 is a developed view showing suction and discharge members of the sealed compressor of FIG. 1.

FIG. 5 is a longitudinal sectional view showing a crankshaft of the sealed compressor of FIG. 1.

FIG. 6 is a view showing results of a temperature in the vicinity of a surface of a discharge pipe of the sealed compressor of FIG. 1.

FIG. 7 is a view showing results of efficiency of the sealed compressor of FIG. 1.

FIG. 8 is a view showing results of evaluation of substances resulting from degradation of lubricating oil in an overload reliability test.

FIG. 9 is a longitudinal sectional view showing major components of a sealed compressor according to Embodiment 3 of the present invention.

FIG. 10 is a longitudinal sectional view showing major components of a sealed compressor according to Embodiment 4 of the present invention.

FIG. 11 is a cross-sectional view showing an internal configuration of a sealed compressor according to Embodiment 5 of the present invention.

FIG. 12 is a longitudinal sectional view showing a sealed compressor according to Embodiment 1 of the present invention.

DESCRIPTION OF EMBODIMENTS

According to an embodiment of the present invention, there is provided a sealed compressor comprising: an electric component; a compression component actuated by the electric component; and a sealed container which accommodates the electric component and the compression component and stores lubricating oil in a bottom portion thereof; a suction pipe for guiding a refrigerant gas suctioned into and compressed by the compression component to an inner space of the sealed container; and a discharge passage for guiding the refrigerant gas compressed by the compression component, from the compression component to outside of the sealed container; wherein the compression component includes: a crankshaft including a main shaft rotated by the electric component and an eccentric shaft which is eccentric with the main shaft; an oil feeding mechanism provided in the main shaft to feed the lubricating oil stored in the bottom portion of the sealed container to slide portions of the compression component; an oil feeding passage provided in the eccentric shaft, communicated with the oil feeding mechanism and having an opening in a surface of the eccentric shaft; and a scattering suppressing section for suppressing the lubricating oil from being scattered from the opening of the oil feeding passage.

In the sealed compressor, the compression component may further include: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; and a cylinder head which is fastened to one end of the block and seals one end of the compression chamber; wherein the scattering suppressing section includes a head separating wall provided integrally with the block and positioned between the cylinder head and the crankshaft.

In the sealed compressor, the opening of the oil feeding passage may be provided in an upper end surface of the eccentric shaft.

In the sealed compressor, the scattering suppressing section may include a sealing lid for closing the opening of the oil feeding passage.

In the sealed compressor, the sealing lid may have a small hole.

In the sealed compressor, the scattering suppressing section may include a guide cover which covers the opening of the oil feeding passage and opens at a lower end surface side of the eccentric shaft.

In the sealed compressor, the compression component may further include: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; and a thrust bearing mechanism which is provided in the block and supports the crankshaft such that the crankshaft is rotatable; wherein the scattering suppressing section may include a scattering direction changing section one end of which is communicated with an opening of the guide cover and the other end of which extends toward the thrust bearing.

In the sealed compressor, the compression component may further include: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; a connecting section for connecting the piston and the eccentric shaft to each other; and a larger-diameter groove formed between the connecting section and the eccentric shaft and communicated with the opening of the oil feeding passage; wherein the scattering suppressing section may include the connecting section which the opening of the oil feeding passage faces, and a closed oil feeding passage which is communicated with the oil feeding passage and is configured such that one end of thereof opens in a lower surface of the eccentric shaft and the other end thereof does not open in the eccentric shaft.

The sealed compressor may further comprise a chamber provided in a portion of the discharge passage and having an inner space defining an expansion space of the refrigerant gas compressed by the compression component.

In the sealed compressor, the scattering suppressing section may include a blocking wall provided between the crankshaft and the chamber.

In the sealed compressor, the compression component may further include: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; a connecting rod, a smaller-end portion of which is rotatably connected to the piston and a larger-end portion of which is rotatably fitted to the eccentric shaft; and a larger-diameter groove formed in an outer peripheral surface of the eccentric shaft in a fitting portion at which the eccentric shaft is fitted to the larger-end portion of the connecting rod or a surface of the larger-end portion of the connecting rod in the fitting portion at which the larger-end portion is fitted to the eccentric shaft; wherein the opening of the oil feeding passage is formed in the outer peripheral surface of the eccentric shaft, and the larger-diameter groove is communicated with the opening; and wherein the scattering suppressing section includes the larger-end portion of the connecting rod, and a closed oil feeding passage formed inside of the eccentric shaft such that the closed oil feeding passage is communicated with the oil feeding passage, one end thereof opens in a lower end surface of the eccentric shaft and the other end thereof is closed.

In the sealed compressor, the valve sub-plate may have a non-contact space in at least one of a surface at the valve plate side and a surface at the cylinder head side, the non-contact space being formed by reducing a wall thickness of the valve sub-plate.

In the sealed compressor, the lubricating oil may have a viscosity which is equal to or less than 8 centistokes at 40 degrees C.

In the sealed compressor, the refrigerant gas may include a cooling medium containing at least one of fluorine atoms and a double bond of oxygen; and the sealed compressor may constitute a closed refrigeration system.

In the sealed compressor, the refrigerant gas may include a hydrocarbon-based cooling medium; and the sealed compressor may constitute a refrigeration system which is limited in an amount of the refrigerant gas filled therein.

The sealed compressor may constitute a refrigeration system for heating.

The sealed compressor may be used for freezing or chilling; and the sealed compressor may constitute a closed refrigeration system in which a compression ratio is greater than 10.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Throughout the drawings, the same or corresponding components are identified by the same reference symbols and will not be described in repetition.

Embodiment 1

FIG. 12 is a longitudinal sectional view showing a sealed compressor 300 according to Embodiment 1 of the present invention.

In FIG. 12, as a scattering suppressing section 455, a sealing lid 455 and a head separating wall 414 are illustrated. Alternatively, a blocking wall 706 of FIG. 11 may be used together with the sealing lid 455, as the scattering suppressing section. Instead of the sealing lid 455, a scattering suppressing section 610 including a guide cover 616 of FIG. 9 and a scattering direction changing section 619 of FIG. 9 may be used. Moreover, instead of the sealing lid 455, a connecting section 355 of FIG. 10 and a closed oil feeding passage 440 (714) 716 of FIG. 10 may be used as the scattering suppressing section.

In FIG. 12, an inclined hole 440 is used as an oil feeding passage. Instead of the inclined hole 440, an inclined hole 714 of FIG. 10 may be used.

In FIG. 12, a spiral groove 368 and a lateral hole 431 are illustrated as an oil feeding mechanism 434. Alternatively, a spiral groove 713 of FIG. 10, a lateral hole 712 of FIG. 10 and a penetrating hole 710 of FIG. 10 may be used as the oil feeding mechanism.

A sealed compressor 300 includes an electric component 331, a compression component 327 actuated by the electric component 331, a sealed container 301 which accommodates the electric component 331 and the compression component 327 and stores lubricating oil 305 in a bottom portion thereof, a suction pipe 324 used to suction a refrigerant gas 309 into an inner space of the sealed container 301 through an opening thereof, and a discharge pipe 425 (discharge passage) used to discharge the refrigerant gas 309 compressed by the compression component 327 from the sealed container 301.

The compression component 327 includes a crankshaft 343 (709) which is rotated by the electric component 331 and includes a main shaft 364 (710) and an eccentric shaft 359 (711) which is eccentric with the main shaft 364 (710), an oil feeding mechanism 368 (708, 712, 713) provided in the main shaft 364 (710), to feed the lubricating oil 305 stored in a bottom portion of the sealed container 301 to slide portions of the compression component 327, an oil feeding passage 440 (714) provided in the eccentric shaft 359 (711) and communicated with the oil feeding mechanism 368 (708, 712, 713) and the scattering suppressing section 455 for suppressing the lubricating oil 305 from being scattered from an opening of the oil feeding passage 440 (714).

In the sealed compressor 300 configured as described above, when the compression component 327 is actuated by the electric component 331, the refrigerant gas 309 is suctioned from the suction pipe 324 into the inner space of the sealed container 301, suctioned from the sealed container 301 into the compression component 321, compressed by the compression component 321, and discharged to the discharge pipe 425.

When the crankshaft 343 (709) is rotated by the electric component 331, the oil feeding mechanism 368 (708, 712, 713) suctions up the lubricating oil 305 stored in the bottom portion of the sealed container 301 and feeds a part of the lubricating oil 305 to the slide portions of the compression component 327. The remaining lubricating oil 305 flows into the oil feeding passage 440 (714) communicated with the oil feeding mechanism 368 (708, 712, 713). At this time, the amount, range or the like of the lubricating oil 305 scattered through the opening of the oil feeding passage 440 (714) is suppressed by the scattering suppressing section 455. For example, by suppressing the lubricating oil 305 from being scattered to the high-temperature members such as the compression component 327, a temperature increase of the lubricating oil 305 is suppressed. The scattered lubricating oil 305 flows into the slide portions of the compression component 327 and lubricates the slide portions. The other components of the sealed compressor 300 are not particularly limited, and may be known components.

In accordance with the sealed compressor 300 as described above, the scattering suppressing section is able to suppress the lubricating oil 305 from being scattered to the high-temperature members. This makes it possible to prevent a situation in which the lubricating oil 305 is applied to the high-temperature members and heats them. Thus, even when the lubricating oil 305 is suctioned up again and scattered, it becomes possible to suppress a situation in which the passages of the refrigerant gas 309, such as the discharge pipe 425 and the cylinder head are heated by the lubricating oil 305. A temperature increase of the refrigerant gas 309 does not occur in these passages, and an increase in a specific volume of the refrigerant gas 309 is suppressed. Therefore, the amount of the refrigerant gas 309 discharged from the compression component 327 is not reduced, and the volumetric efficiency of the sealed compressor 300 can be maintained.

In addition to the above, it is possible to prevent a situation in which the scattered lubricating oil 305 is heated by the high-temperature members and thereby vaporized. This makes it possible to prevent a situation in which the vaporized lubricating oil 305 is suctioned into the compression component 327, and thereby the internal volume of the compression component 327 is reduced. As a result, the amount of the refrigerant gas 309 suctioned into and discharged from the compression component 327 is not reduced, and thereby the volumetric efficiency of the sealed compressor 300 can be maintained.

Furthermore, it is possible to prevent a situation in which the refrigerant gas 309 is heated by the scattered lubricating oil 305. Because of this, the amount of the refrigerant gas 309 suctioned into the compression component 327 is not lessened, and a reduction of the volumetric efficiency of the sealed compressor 300 can be suppressed.

Moreover, it is possible to prevent a situation in which the lubricating oil 305 is degraded by heat. It is also possible to prevent a situation in which the members made of organic substances are degraded by the high-temperature lubricating oil 305. Therefore, the capability of the lubricating oil 305 and the capability of the members can be maintained, the sealed compressor 300 can perform its function and a reduction of the life of the sealed compressor 300 can be prevented.

Embodiment 2

In Embodiment 2 of the present invention, the sealed compressor of Embodiment 1 is applied to a reciprocating sealed compressor.

FIG. 1 is a longitudinal sectional view showing the sealed compressor 300. FIG. 2 is a cross-sectional (transverse-sectional) view showing the sealed compressor 300. FIG. 4 is a developed view showing suction and discharge members in the sealed compressor 300. FIG. 5 is a longitudinal sectional view showing the crankshaft 343 of the sealed compressor 300.

The sealed compressor 300 includes the sealed container 301.

The sealed container 301 is manufactured by, for example, drawing process of an iron plate. The lubricating oil 305 is stored in the bottom portion of the sealed container 301. The sealed container 301 is filled with the refrigerant gas 309. As examples of the refrigerant gas 309, there are a refrigerant containing fluorine atoms or a double bond of oxygen, such as HFC-134a and HFC-1234yf, and a HC refrigerant such as HC-600a and HC-290. HFC-134a is low in ozone depletion potential, while HFC-1234yf is low in ozone depletion potential and global warming potential. A suction pipe 324 used to suction the refrigerant gas 309 is connected to the sealed container 301.

The suction pipe 324 serves to introduce the refrigerant gas 309 suctioned into and compressed by the compression component 327, into the inner space of the sealed container 301. The suction pipe 324 has at one end thereof an opening 312 communicated with the interior of the sealed container 301. The other end of the suction pipe 324 is connected to a lower-pressure side 320 of a refrigeration unit 316.

A compression body 335 includes the compression component 327 and the electric component 331 for actuating the compression component 327. The compression body 335 is accommodated into the container 301 and is elastically supported on the container 301 by a suspension spring 339. The elastic support mechanism of the compression body 335 is not limited to this. As such a mechanism, a known desired configuration may be used.

The electric component 331 includes a stator 372 and a rotor 376. The stator 372 is fastened to a lower side of a block 347 by, for example, a bolt. The rotor 376 is placed coaxially at an inner side of the stator 372 and fastened to the main shaft 364 by, for example, shrink fitting (shrinkage-fit).

The compression component 327 includes the crankshaft 343, the block 347, a piston 351, and a connecting section 355.

The block 347 includes a cylinder 384 and a bearing unit 388. Each of the cylinder 384 and the bearing unit 388 has a substantially cylindrical shape. The cylinder 384 and the bearing unit 388 are placed such that their axes cross each other at an approximately right angle.

The bearing unit 388 supports the main shaft 364 such that the main shaft 364 is rotatable. An upper end of the bearing unit 388 supports the crankshaft 343 via a thrust bearing mechanism 464 such that the crankshaft 343 is rotatable. The thrust bearing mechanism 464 includes balls and a cage.

A valve plate 398, a suction valve 401 and a cylinder head 404 are fastened to an end surface of the cylinder 384 by a head bolt 407. This allows an opening end 385 of the end surface of the cylinder 384 to be sealed. The valve plate 398 includes a suction hole 392 and a discharge hole 395. The suction hole 392 is opened and closed by the suction valve 401. The discharge hole 395 is opened and closed by the discharge valve 402.

A valve sub-plate 413 is interposed between the cylinder head 404 and the valve plate 398 via gaskets 416 placed on both surfaces of the valve sub-plate 413, respectively. The valve sub-plate 413 has a non-contact space 419. The non-contact space 419 is formed by reducing a wall thickness of the valve sub-plate 413. The non-contact space 419 provides a partial gap between the valve plate 398 and the valve sub-plate 413. The non-contact space 419 serves to suppress heat from migrating between the high-temperature cylinder head 404 and the block 347. Alternatively, the non-contact spaces 419 may be provided on the both surfaces of the valve sub-plate 413 as necessary.

A suction muffler 410 is fastened to the end surface of the cylinder 384 by the valve plate 398 and the cylinder head 404. The suction muffler 410 is molded using synthetic resin such as PBT added with glass fibers. The suction muffler 410 includes a communicating pipe 422. The communicating pipe 422 guides the refrigerant gas 309 to the interior of a compression chamber 380.

The discharge passage discharges the refrigerant gas 309 compressed by the compression component 327, from the compression component 327 to outside of the sealed container 301. The discharge passage includes a discharge space 405, a discharge communicating pipe 425 a, a chamber 470, a discharge pipe 425 and a discharge pipe 473. These members are communicated with each other, to discharge the refrigerant gas 309 from the compression chamber 380.

The discharge space 405 is formed inside of the cylinder head 404. The discharge space 405 is communicated with the compression chamber 380 via the discharge hole 395, and is communicated with the discharge communicating pipe 425 a.

The discharge communicating pipe 425 a is communicated with the discharge space 405 and the chamber 407.

The chamber 470 is communicated with the discharge communicating pipe 425 a and the discharge pipe 425, and is provided in a portion of the discharge passage. The chamber 470 has an inner space defining an expansion space 467 of the refrigerant gas 309 compressed by the compression component 327.

The discharge pipe 425 is connected to the discharge pipe 473, which penetrates the sealed container 301.

The compression chamber 380 is formed inside of the cylinder 384.

The piston 351 is reciprocatingly inserted into the compression chamber 380. The piston 351 has an inner space 352 which opens in the compression chamber 380. The piston 351 is connected to a connecting section 355 via a piston pin 351.

The connecting section 355 converts a rotational motion of the eccentric shaft 359 into a reciprocation motion, and transmits the reciprocation motion to the piston 351. The connecting section 355 includes a larger-diameter portion and a smaller-diameter portion. The larger-diameter portion is rotatably fitted to the eccentric shaft 359. The smaller-diameter portion is rotatably coupled to the piston 351 via the piston pin 351. A larger-diameter groove is formed in an outer peripheral surface of the eccentric shaft 359 in a fitting portion at which the eccentric shaft 359 and the larger-end portion of the connecting portion 355 are fitted to each other, or in a surface of the larger-end portion in the fitting portion at which the larger-end portion and the eccentric shaft 359 are fitted to each other. That is, the larger-end portion has a larger-diameter hole to which the eccentric shaft 359 is fitted. A larger-diameter groove is formed in the inner peripheral surface of the larger-diameter hole or in the outer peripheral surface of the eccentric shaft 359 in the fitting portion. The smaller-diameter portion has a smaller-diameter hole to which the piston pin 351 is fitted. A smaller-diameter groove is formed in an inner peripheral surface of the smaller-diameter hole or in an outer peripheral surface of the piston pin 351 in the fitting portion. The connecting section 355 includes a communicating hole 356 and a rod hole 446. The communicating hole 356 communicates the smaller-diameter groove and the inner space 352 of the piston 351 with each other. The rod hole 446 communicates the larger-diameter groove and the smaller-diameter groove with each other.

The crankshaft 343 includes the main shaft 364 rotated by the electric component 331 and the eccentric shaft 359 which is eccentric with the main shaft 364. A pump unit 428 is attached to a lower portion of the main shaft 364. As examples of the pump unit 428, there are displacement pumps such as a coaxial core centrifugal pump, a centrifugal pump, a viscosity pump, and a trochoid pump. A lower portion of the main shaft 364 and the pump unit 428 are immersed in the lubricating oil 305. The main shaft 364 is provided with the oil feeding mechanism 368.

The oil feeding mechanism 368 feeds the lubricating oil 305 stored in the bottom portion of the sealed container 301 to the slide portions of the compression component 327. The oil feeding mechanism 368 includes a penetrating passage 433 penetrating inside of the main shaft 364 and a spiral groove 434 formed in an outer peripheral surface of the main shaft 364.

A lower end of the penetrating passage 433 communicates with the pump unit 428, while an upper end of the penetrating passage 433 opens in an upper end of the main shaft 364. A lower portion of the penetrating passage 433 is wider than an upper portion of the penetrating passage 433. The lateral hole 431 is provided in the lower portion of the penetrating passage 433. An upper end opening of the penetrating passage 433 is located in the vicinity of the thrust bearing mechanism 464.

One end of the lateral hole 431 is communicated with the penetrating passage 433, while the other end thereof opens in the surface of the main shaft 364.

A lower end of the spiral groove 434 is connected to the lateral hole 431. An upper end of the spiral groove 434 is communicated with an upper end of the inclined hole 440. The spiral groove 434 extends through the slide portions 437 of the main shaft 364 and of the bearing unit 388.

The inclined hole 440 (oil feeding passage) is provided in the eccentric shaft 359. The inclined hole 440 penetrates inside of the eccentric shaft 359 and has an opening hole (opening) 452 in an upper end surface of the eccentric shaft 359. The inclined hole 440 is inclined in a direction from the main shaft 364 toward a center in the eccentric shaft 359, from its lower end toward its upper end. A lower end of the inclined hole 440 is communicated with the oil feeding mechanism 368. The inclined hole 440 is communicated with the larger-diameter groove of the connecting section 355, in a portion between its upper end and its lower end. The opening hole 452 at the upper end of the inclined hole 440 is located at an upper end 449 of the eccentric shaft 359. The scattering suppressing section 455 is provided at the upper end 449 of the eccentric shaft 359.

The scattering suppressing section 455 suppresses the lubricating oil 305 from being scattered from the opening hole 452 of the inclined hole 440. In the present embodiment, the scattering suppressing section 455 is formed by the sealing lid 458. The sealing lid 458 is fastened to the opening hole 452, by, for example, press fit. In this way, the sealing lid 458 closes the opening hole 452 at the upper end of the inclined hole 440. A small hole 461 penetrating the sealing lid 458 is formed in an upper surface of the sealing lid 458.

The small hole 461 communicates the interior of the sealed container 301 and the inclined hole 440 with each other. The small hole 461 serves to prevent occurrence of a pressure difference between the interior of the sealed container 301 and the inclined hole 440. The small hole 461 preferably has a diameter which is smaller than 1 mm. The small hole 461 is placed above the discharge pipe 425 and the chamber 470 and extends vertically.

The sealed compressor 300 having the above described configuration constitutes a refrigeration system of FIG. 3.

The sealed container 301 is connected to the refrigeration unit 316 via the discharge pipe 473.

The refrigeration unit 316 includes a condenser 476, an expansion unit 477, and an evaporator 478. The condenser 476 condenses the refrigerant gas 309 discharged from the discharge pipe 473. The expansion unit 477 includes an expansion valve, a capillary tube, etc., and expands the refrigerant gas 309 from the condenser 476. The evaporator 478 evaporates the refrigerant gas 309 from the expansion unit 477. The evaporated refrigerant gas is suctioned into the suction pipe 324 of the sealed compressor 300.

In a case where the condenser 476 is used for heating, the refrigeration unit 316 becomes a refrigeration system constituting a heat pump.

In a case where the refrigeration system uses a combustible refrigerant such as a HC refrigerant, a total amount of the refrigerant gas 309 is sometimes limited.

A refrigeration cycle is a closed cycle as it is incorporated into a refrigerator, or the like. The refrigeration cycle is a closed refrigeration system incorporated into a refrigerator, an automatic vending machine, etc., and is used for cooling, or heating (heat pump).

Next, a description will be given of the operation and function of the sealed compressor 300 configured as described above, in conjunction with the refrigerant gas 309.

When the stator 372 is applied with a current and generates a magnetic field, the rotor 376 rotates and the main shaft 364 fastened to the rotor 376 rotates. According to the rotation of the main shaft 364, the eccentric shaft 359 performs a rotational motion. The connecting section 355 converts the rotational motion of the eccentric shaft 359 into a reciprocation motion of the piston 351.

When the piston 351 is moving from a top dead center toward a bottom dead center, the volume of the compression chamber 380 of the cylinder 384 increases and the refrigerant gas 309 inside of the compression chamber 380 expands. When the pressure in the compression chamber 380 becomes lower than a suction pressure, the suction valve 401 opens because of a difference between the pressure in the compression chamber 380 and a pressure in the suction muffler 410. The refrigerant gas 309 flows from the refrigeration unit 316 into the sealed container 301 via the suction pipe 324. The refrigerant gas 309 flows from the sealed container 301 into the compression chamber 380 through the communicating pipe 422.

When the piston 351 is moving from the bottom dead center toward the top dead center, the volume of the compression chamber 380 decreases, and the pressure in the compression chamber 380 increases. Then, because of a difference between the pressure in the compression chamber 380 and the pressure in the suction muffler 410, the suction valve 401 closes. Then, when the pressure in the compression chamber 380 exceeds a pressure in the discharge space 405 of the cylinder head 404, the discharge valve 402 opens. As a result, the refrigerant gas 309 which has been compressed and raised its temperature is discharged into the discharge space 405 through the discharge hole 395 of the valve plate 398. The refrigerant gas 309 flows into the expansion space 467 of the chamber 470 via the discharge communicating pipe 425 a. Through the discharge pipe 425 and the discharge pipe 473, the refrigerant gas 309 is discharged from the sealed compressor 300.

The refrigerant gas 309 flows from the sealed compressor 300 into the refrigeration unit 316. The refrigerant gas 309 is caused to radiate heat in the condenser 476, and then expanded in the expansion unit 477, so that the pressure of the refrigerant gas 309 is lowered. The refrigerant gas 309 with the lowered pressure absorbs ambient heat in the evaporator 478, and returns from the lower-pressure side 320 to the suction pipe 324 of the sealed compressor 300.

Next, a description will be given of the operation and function of the sealed compressor 300 configured as described above, in conjunction with the lubricating oil 305.

When the rotor 376 rotates the main shaft 364, the lubricating oil 305 stored in the bottom portion of the sealed container 301 is suctioned up by the pump unit 428. The lubricating oil 305 flows upward through a lower portion of the penetrating passage 433.

A part of the lubricating oil 305 further flows upward to an upper region of the penetrating passage 433. When the lubricating oil 305 reaches the upper end of the bearing unit 388, it flows out of the upper end opening of the penetrating passage 433 and lubricates the thrust bearing mechanism 464.

The remaining lubricating oil 305 flows from the lateral hole 431 into the spiral groove 434. The lubricating oil 305 flows upward through the spiral groove 434 by a centrifugal force. During this time, a portion of the lubricating oil 305 flows into a region between the bearing unit 388 and the main shaft 364 and lubricates the slide portions 437 of the bearing unit 388 and the main shaft 364.

Furthermore, the remaining lubricating oil 305 flows from the upper end of the spiral groove 434 into the inclined hole 440. The lubricating oil 305 flows upward through the inclined hole 440. A part of this lubricating oil 305 flows out to the larger-diameter groove, then flows through the rod hole 446, and then flows from the communicating hole 356 into the inner space 352 of the piston 351 via the smaller-diameter groove. Then, the lubricating oil 305 flows from the inner space 352 of the piston 351 into the compression chamber 380, and lubricates the slide portions of the piston 351 and of the cylinder 384.

Moreover, the remaining lubricating oil 305 further flows upward through the inclined hole 440. However, since the opening hole 452 of the inclined hole 440 is closed by the sealing lid 458 of the scattering suppressing section 455, the lubricating oil 305 does not flow out of the opening hole 452.

When the lubricating oil 305 flows into the inclined hole 440, the pressure in the inclined hole 440 increases. At this time, air in the inclined hole 440 is discharged from the small hole 461 of the sealing lid 458, so that an increase in the pressure in the inclined hole 440 is suppressed. This allows the lubricating oil 305 to smoothly flow into the inclined hole 440 and move upward therethrough. On the other hand, when the lubricating oil 305 flows out of the inclined hole 440, the pressure in the inclined hole 440 decreases. At this time, the air in the inclined hole 440 is suctioned into the small hole 461 of the sealing lid 458, so that a decrease in the pressure in the inclined hole 440 is suppressed. This allows the lubricating oil 305 to smoothly flow out of the inclined hole 440.

When the lubricating oil 305 is suctioned up by the pump unit 428, the refrigerant gas 309 contained in the lubricating oil 305 is suctioned up together. A most part of the refrigerant gas 309 is separated through a gas release hole of the pump unit 428, or the like. The remaining refrigerant gas 309 is released through the small hole 461 of the sealing lid 458. At this time, a small amount of the lubricating oil 305 flows out of the small hole 461 together with the refrigerant gas 309. According to the inventors' experiment, it was confirmed that the lubricating oil 305 is not scattered when the diameter of the small hole 461 is equal to or less than φ1.

Because of the above, it becomes possible to prevent a situation in which the refrigerant gas 309 contained in the lubricating oil 305 is formed into small air bubbles and given to the slide portions 437. Therefore, it becomes possible to prevent a situation in which the small air bubbles of the refrigerant gas 309 make holes in an oil film of the lubricating oil 305 formed in the slide portions 437. This enables the lubricating oil 305 to smoothly lubricate the slide portions 437 without causing a friction and a wear of the slide portions 437 to progress due to the holes formed in the oil film.

In addition, the small hole 461 is placed above the discharge pipe 425 and the chamber 470 and extends vertically. Therefore, even if the lubricating oil 305 flows out of the small hole 461, it does not adhere to the discharge pipe 425 and the chamber 470. As a result, the refrigerant gas 309 flowing through the discharge pipe 425 and the chamber 470 is not heated by the lubricating oil 305.

In accordance with the sealed compressor 300 having the above described configuration, the sealing lid 458 of the scattering suppressing section 455 serves to prevent the lubricating oil 305 from being scattered from the opening hole 452 into the sealed container 301. Because of this, it becomes possible to prevent a situation in which the lubricating oil 305 is applied to the high-temperature members and thereby heated. Therefore, the high-temperature lubricating oil 305 does not heat the passage of the refrigerant gas 309 and the refrigerant gas 309 does not raise its temperature. As a result, the amount of the refrigerant gas 309 discharged from the compression chamber 380 is not reduced, and hence the volumetric efficiency of the sealed compressor 300 can be maintained.

It should be especially noted that the lubricating oil 305 is not applied to the valve sub-plate 413. Thus, it becomes possible to prevent a situation in which the lubricating oil 305 stays in the non-contact space 419 and transfers heat from the high-temperature cylinder head 404 to the block 347. As a result, the temperature of the compression chamber 380 of the block 347 can be lowered, and the temperature of the compressed refrigerant gas 309 can be lowered averagely. A heat loss of the refrigerant gas 309 during the compression can be reduced, and a temperature increase of the refrigerant gas 309 inside of the sealed container 301 and of the refrigerant gas 309 suctioned into the sealed container 301 can be suppressed. Thus, the volumetric efficiency of the sealed compressor 300 can be improved.

Since the lubricating oil 305 is not scattered and vaporized, it becomes possible to prevent a situation in which the vaporized lubricating oil 305 reduces the internal volume of the compression chamber 380. Therefore, the amount of the refrigerant gas 309 suctioned into and discharged from the pressure chamber 380 is not reduced, and the volumetric efficiency of the sealed compressor 300 can be maintained.

Furthermore, it becomes possible to prevent a situation in which the scattered lubricating oil 305 heats the refrigerant gas 309. Because of this, the specific volume of the refrigerant gas 309 does not increase and a reduction of the volumetric efficiency of the sealed compressor 300 can be suppressed.

Even when HFO-1234yf having a double bond, which is unstable in physical property, is used as the refrigerant gas 309, decomposition of HFO-1234yf is suppressed. Or, even when the refrigerant gas 309 containing fluorine atoms, such as HFC 134a is used, it is possible to suppress occurrence of hydrolysis of the refrigerant gas 309 due to a little moisture, etc., contained in the lubricating oil 305, and exist inside of the sealed container 301. This enables the refrigerant gas 309 to perform its function without being degraded. As a result, the refrigeration system including the sealed compressor 300 can extend its life.

Also, it becomes possible to prevent a situation in which the lubricating oil 305 is degraded by heat transferred from the high-temperature members. In addition, it becomes possible to prevent a situation in which the members made of organic substances are degraded by the high-temperature lubricating oil 305. Therefore, a possibility that degraded organic substances adhere to the members such as the expansion valve and the expansion pipe is low. This makes it possible to keep capabilities of the lubricating oil 305, the members, and the like and prevent a reduction of the life of the sealed compressor 300, which would be caused by heat.

Since the sealing lid 458 prevents the lubricating oil 305 from being scattered from the opening hole 452, the lubricating oil 305 fed from the inclined hole 440 to the slide portions of the piston 351 and of the cylinder 384 via the rod hole 446 increases in amount. Therefore, a driving power loss in the sealed compressor 300 can be reduced and seizing or the like can be prevented, thereby extending the life of the sealed compressor 300.

By merely inserting the sealing lid 458 into the opening hole 452 at the upper end of the inclined hole 440, scattering of the lubricating oil 305 is suppressed. This allows the use of the existing crankshaft 343 having the inclined hole 440, which can suppress an increase in cost.

Furthermore, the chamber 470 is apart from the suction sections such as the suction pipe 324 and the suction muffler 410. Thus, heat transfer from the chamber 470 to the suction sections can be lessened, and hence a temperature increase of the refrigerant gas 309 flowing through the suction sections can be suppressed. As a result, a high efficiency of the sealed compressor 300 can be realized.

Moreover, the chamber 470 is connected to the discharge pipe 425 and is separate from the compression chamber 380. This makes it easier to change the chamber 470 into one having a different interval volume. Therefore, the internal volume of the chamber 470 for muffling (silencing) a noise of the discharged refrigerant gas 309 can be easily changed as desired.

Next, the temperature of the discharge pipe 425 in the sealed compressor 300 will be described.

FIG. 6 shows a temperature in the vicinity of the surface of the discharge communicating pipe 425 a of the discharge pipe 425 in the sealed compressor 300 having the above described configuration, and a temperature in the vicinity of the surface of the discharge pipe 425 in the conventional sealed compressor. It should be noted that in the conventional sealed compressor, the sealing lid of the scattering suppressing section is not fitted to the opening hole of the inclined hole.

The temperature in the vicinity of the surface of the discharge communicating pipe 425 a in the sealed compressor 300 was 80 degrees C. The temperature in the vicinity of the surface of the discharge pipe 425 in the conventional sealed compressor was 90 degrees C. As can be seen from this, the temperature of the discharge communicating pipe 425 a in the sealed compressor 300 was lower than the temperature of the discharge pipe 425 in the conventional sealed compressor, by about 10 degrees C.

From the above results, it could be seen that the lubricating oil 305 scattered from the opening hole 452 raised the temperature of the discharge communicating pipe 425 a by about 10 degrees C. In other words, it was found out that by preventing the lubricating oil 305 from being scattered by using the sealing lid 458 of the scattering suppressing section 455, a temperature increase of the discharge communicating pipe 425 a which would be caused by the lubricating oil 305 scattered, could be suppressed.

Next, the efficiency of the sealed compressor 300 will be described.

FIG. 7 shows the efficiency of the sealed compressor 300 having the above described configuration and the efficiency of the conventional sealed compressor. The conventional sealed compressor is the sealed compressor 300 used in temperature measurement of FIG. 6. In FIG. 7, a vertical axis indicates a value obtained by dividing COP (coefficient of performance)=cooling ability W by an input W, as the efficiency of the sealed compressor 300.

The efficiency of the sealed compressor 300 is 1.84 W/W. The efficiency of the conventional sealed compressor is 1.80 W/W. Thus, the efficiency of the sealed compressor 300 is higher than the efficiency of the conventional sealed compressor by 0.04.

From the above results, the following is estimated. By preventing the lubricating oil 305 from being scattered by using the sealing lid 458 of the scattering suppressing section 455, a temperature increase of the lubricating oil 305 can be suppressed. Thus, since the discharge communicating pipe 425 a is not heated by the high-temperature lubricating oil 305 as described above, a temperature increase of the refrigerant gas 309 flowing therethrough can be suppressed. In addition, it becomes possible to prevent a situation in which the refrigerant gas 309 is heated by the scattered high-temperature lubricating oil 305. Because of this, the specific volume of the refrigerant gas 309 is not increased, and the amount of the refrigerant gas 309 suctioned into the compression chamber 380 is not reduced. This makes it possible to ensure the amount of the refrigerant gas 309 discharged from the compression chamber 380, and hence improve the efficiency of the sealed compressor.

Because of improvement of the efficiency as described above, a cylinder volume (maximum volume of the compression chamber 380) of the sealed compressor 300 can be reduced, and the sealed compressor 300 can be reduced in size.

As the specific volume of the refrigerant gas 309 increases, a compression ratio of the refrigerant gas 309 inside of the compression chamber 380 increases. According to the inventors' study, it was revealed that if the compression ratio exceeds 10, the temperature of the compressed refrigerant gas 309 significantly increases. Therefore, if scattering of the lubricating oil 305 is prevented by the sealing lid 458, the refrigerant gas 309 is not heated by the high-temperature lubricating oil 305, and its specific volume does not increase. Thus, the compression ratio of the refrigerant gas 309 inside of the compression chamber 380 is low, and the temperature increase of the refrigerant gas 309 can be suppressed. That is, it becomes possible to avoid a synergetic effect, in which the refrigerant gas 309 is heated by the high-temperature lubricating oil 305, the high-temperature refrigerant gas 309 is compressed and further raises its temperature, and the resulting heat heats the interior of the sealed container 301 and further raises the temperature of the refrigerant gas 309. As a result, the temperature of the lubricating oil 305 and the temperature of the refrigerant gas 309 can be lowered effectively.

Next, a relationship between kinds of the refrigerant gas 309 and viscosity grades of the lubricating oil 305 will be described.

FIG. 8 shows results of evaluation of the lubricating oil 305 inside of the cylinder head 404 (valve, etc.) in an overload reliability test. FIG. 8 shows the amounts of substances resulting from degradation of the lubricating oil 305 and the refrigerant gas 309, corresponding to the viscosity grades (kinetic viscosities [mm²/second] at 40 degrees C.) of the lubricating oil 305.

In the conventional sealed compressor (temperature of compression chamber: 145 degrees C.), it was observed that the substances resulting from degradation of the lubricating oil 305 and the refrigerant gas 309 were generated in the lubricating oil 305 of the viscosity grades of VG 8 to VG3. By comparison, in the sealed compressor 300 (temperature of compression chamber 380: 135 degrees C.), the substances resulting from degradation of the lubricating oil 305 and the refrigerant gas 309 were not observed in all of the lubricating oil 305 of the viscosity grades of VG 10 to VG3. Also, in the sealed compressor 300 (temperature of compression chamber 380: 140 degrees C.), the substances resulting from degradation of the lubricating oil 305 and the refrigerant gas 309 were not observed in the lubricating oil 305 of the viscosity grades of VG 10 to VG5.

Thus, in the sealed compressor 300, it is possible to prevent, by using the sealing lid 458 of the scattering suppressing section 455, a situation in which the lubricating oil 305 is applied to the high-temperature member and thereby heated. Because of this, it is estimated that it becomes possible to suppress degradation of the lubricating oil 305 due to heat, and suppress generation of the substances resulting from degradation, even in the lubricating oil 305 which is low in viscosity grade.

As the viscosity grade of the lubricating oil 305 decreases, molecular weight of molecules of the lubricating oil 305 decreases, and reaction energy associated with heat decreases. Therefore, in this state, heat decomposition occurs quickly and the substances resulting from degradation are generated. Also, a heat degradation reaction of the lubricating oil 305 depends on the kind of the lubricating oil 305, and the kind and temperature of the refrigerant gas 309.

The refrigerant gas 309 having a double bond, such as HFO-1234yf, is easily decomposed. The refrigerant gas 309 containing fluorine atoms, such as HFC-134a, is easily degraded by heat and hydrofluoric acid, if the hydrofluoric acid is generated due to heat. As the refrigerant gas 309 having polarity such as HFO-134a, oil such as ester oil is typically used, in view of mutual solubility with the lubricating oil 305. The ester oil is easily degraded by hydrolysis.

As the viscosity of the lubricating oil 305 decreases, a viscosity friction loss of the slide portions 437 is reduced. In view of this, the lubricating oil 305 of a low viscosity is preferably used. When the viscosity of the lubricating oil 305 at 40 degrees C. is equal to or less than 8 centistokes (grade: VG8), the driving power loss in the sealed compressor 300 can be lessened, and the efficiency of the whole refrigeration unit 316 can be made higher.

In the closed refrigeration cycle, such as the refrigerator, if the lubricating oil 305 or the refrigerant gas 309 is degraded, the substances resulting from the degradation are circulated within the closed cycle. If these substances are deposited on the sections such as expansion unit 477, these sections become incapable of performing their functions, which will reduce the life of the refrigeration unit 316. By comparison, in the sealed compressor 300, degradation of the lubricating oil 305 and of the refrigerant gas 309 is lessened. Therefore, the respective sections can perform their function, and the life of the refrigeration unit 316 can be extended.

In a case where the refrigeration system of the refrigeration unit 316 is used for heating (heat pump), it is required that the temperature of the discharged refrigerant gas 309 be high. Because an increase in the internal temperature of the sealed compressor 300 is lessened, a temperature decrease of the discharged refrigerant gas 309 is less. Therefore, the high-temperature refrigerant gas 309 is efficiently discharged from the sealed compressor 300.

In a case where a combustible refrigerant such as HC-600a and HC-290 is used as the refrigerant gas 309, it is necessary to reduce a total amount of the refrigerant gas 309 for the sake of safety. Since the volumetric efficiency of the sealed compressor 300 is high, the amount of the refrigerant gas 309 filled into the sealed compressor 300 can be reduced. Therefore, irrespective of the kind of the refrigerant gas 309, safety of the sealed compressor 300 can be improved, and cost of the sealed compressor 300 can be reduced.

As the sealed compressor 300 of the closed cycle, using the refrigerant gas 309 containing the combustible refrigerant, it is desirable to use a reciprocating compressor of an internal low-pressure type, including the sealed container 301 of a low-pressure. Thus, the refrigerant gas 309 which is very low in ozone depletion potential and global warming potential, is used, and global environment is protected.

Embodiment 3

FIG. 9A is a longitudinal sectional view showing major components of the sealed compressor 300. FIG. 9B shows the scattering suppressing section 610 fitted to the opening hole 452.

The scattering suppressing section 610 serves to suppress the lubricating oil 305 from flowing out of the opening hole 452 provided in the eccentric shaft 359. The scattering suppressing section 610 includes the guide cover 616 and the scattering direction changing section 619.

The guide cover 616 covers the opening hole 452 and receives the lubricating oil 305 flowing out of the opening hole 452. The guide cover 616 has a substantially cylindrical shape having an upper surface. The guide cover 616 is fixed such that its cylindrical lower portion is fitted into the opening hole 452. A portion of the guide cover 616 protrudes radially outward and opens at a lower end surface side of the eccentric shaft 359.

The scattering direction changing section 619 guides the lubricating oil 305 received by the guide cover 616 toward the thrust bearing mechanism 464. The upper end of the scattering direction changing section 619 is communicated with the opening of the guide cover 616. The scattering direction changing section 619 is inclined in a direction away from the larger-diameter portion of the eccentric shaft 359 toward the lower end.

The head separating wall 414 is included in the scattering suppressing section 610. The head separating wall 414 is formed in an upper portion of the block 347 and extends upward from the block 347. The head separating wall 414 is provided at an opposite side of the guide cover 616 with respect to the opening hole 452. In other words, the opening hole 452 is located between the head separating wall 414 and the guide cover 616. The head separating wall 414 is provided at the side of the cylinder head 404 (FIG. 1) and the valve sub-plate 413 (FIG. 1).

Next, a description will be given of the operation and function of the sealed compressor 300 configured as described above.

When the lubricating oil 305 is suctioned up to the upper end of the eccentric shaft 359 by the oil feeding mechanism 368, it flows through the inclined hole 440 and flows out of the opening hole 452. The lubricating oil 305 contacts the guide cover 616 of the scattering suppressing section 610. Thus, the lubricating oil 305 is suppressed from being scattered into the interior of the sealed container 301.

A part of the lubricating oil 305 returns to the inclined hole 440.

The remaining lubricating oil 305 is guided from the guide cover 616 in a downward direction along the scattering direction changing section 619. Then, the lubricating oil 305 is fed to the thrust bearing mechanism 464 and lubricates the slide portions of the thrust bearing mechanism 464.

In the thrust bearing mechanism 464, balls slide in a point-contact state. The sliding in the point-contact state provides a very high pressure and harsh conditions as compared to sliding in a surface-contact state, such as sliding of a plain bearing. However, the scattering suppressing section 610 forcibly feeds the lubricating oil 305 to the thrust bearing mechanism 607. Therefore, the lubricating oil 305 can sufficiently lubricate the slide portions in the point-contact state. Thus, seizing or the like can be prevented, and the life of the sealed compressor 300 can be extended.

Even if the lubricating oil 305 is discharged from the opening hole 452 to an opposite side of the guide cover 616, the head separating wall 414 prevents the lubricating oil 305 from being scattered toward the valve sub-plate 413. Because of this, heat is not transferred from the cylinder head 404 to the block 347 via the lubricating oil 305 staying in the non-contact space 419. Therefore, a temperature increase of the refrigerant gas 309 can be suppressed, and the volumetric efficiency of the sealed compressor 300 can be improved. In addition, since the head separating wall 414 is integral with the block 347, the number of members does not increase and an increase in cost can be suppressed.

The scattering suppressing section 610 prevents the lubricating oil 305 from being scattered from the opening hole 452. Thus, the lubricating oil 305 is not applied to the passage of the refrigerant gas 309 such as the discharge pipe 425 and the high-temperature members. Because of this, a temperature increase of the lubricating oil 305, a temperature increase of the refrigerant gas 309, and a temperature increase of the interior of the sealed container 301, can be suppressed. As a result, the volumetric efficiency of the sealed compressor 300 can be improved, and the life of the sealed compressor 300 can be extended.

Embodiment 4

FIG. 10 is a longitudinal sectional view showing major components of the sealed compressor 300.

The main shaft 710 is provided with an oil feeding mechanism. The oil feeding mechanism includes the penetrating passage 708 penetrating inside of the main shaft 710 and the spiral groove 713 formed in the outer peripheral surface of the main shaft 710.

The penetrating passage 708 is configured such that its lower end is communicated with the pump unit 428 and its upper end opens in an oil feeding groove 717 at the upper end of the main shaft 710. The lateral hole 431 of the penetrating passage 433 opens in the main shaft 710 and is communicated with the spiral groove 713.

The inclined hole 714 (oil feeding passage) penetrates inside of the eccentric shaft 711. The inclined hole 440 is inclined in a direction from a center toward the outer peripheral surface in the eccentric shaft 359, from its lower end toward its upper end. A lower end of the inclined hole 714 is communicated with the oil feeding groove 717. The inclined hole 714 is communicated with the oil feeding mechanism via the oil feeding groove 717. The opening of the inclined hole 714 is formed in the outer peripheral surface of the eccentric shaft 359 and is communicated with the larger-diameter groove formed in the larger-end portion of the connecting section 355 or the larger-diameter groove formed in the eccentric shaft 359. The inclined hole 714 crosses and is communicated with a closed oil feeding passage 716.

The closed oil feeding passage 716 is formed inside of the eccentric shaft 359 such that the closed oil feeding passage 716 is communicated with the inclined hole 714, one end thereof opens in a lower end surface of the eccentric shaft 359 and the other end thereof is closed. That is, the closed oil feeding passage 716 axially penetrates inside of the eccentric shaft 711. An upper end of the closed oil feeding passage 716 does not open to outside but is closed inside of the eccentric shaft 711. A lower end of the closed oil feeding passage 716 opens in the thrust bearing mechanism 464.

Next, a description will be given of the operation and function of the sealed compressor 300 configured as described above.

The lubricating oil 305 is suctioned up by the pump unit 428, and flows upward through the penetrating passage 708.

A part of the lubricating oil 305 flows out of the lateral hole 712 and to the spiral groove 713. While the lubricating oil 305 is flowing through the spiral groove 713, it enters a region between the crankshaft 709 and the bearing unit 388, and lubricates the slide portions 437 of the crankshaft 709 and of the bearing unit 388. The lubricating oil 305 reaches the upper end of the spiral groove 713 and flows out to the oil feeding groove 717.

The remaining lubricating oil 305 further flows upward through the penetrating passage 708, reaches the upper end of the main shaft 710 and flows out to the oil feeding groove 717.

The lubricating oil 305 in the oil feeding groove 717 flows into the thrust bearing mechanism 464 and lubricates the thrust bearing mechanism 464. The lubricating oil 305 flows from the oil feeding groove 717 into the inclined hole 714 and flows upward through the inclined hole 714.

A part of the lubricating oil 305 in the inclined hole 714 flows into the closed oil feeding passage 716, flows downward through the closed oil feeding passage 716, and then flows out. The lubricating oil 305 is fed toward the thrust bearing mechanism 464 and lubricates the slide portions of the thrust bearing mechanism 464.

A part of the remaining lubricating oil 305 in the inclined hole 714 flows out to the larger-diameter groove of the connecting section 355. The lubricating oil 305 flows through the rod hole 446 and then flows through the communicating hole 356 via the smaller-diameter groove. The lubricating oil 305 flows out of the communicating hole 356 and to the inner space 352 of the piston 351, enters the slide portions of the piston 351 and of the cylinder 384, and lubricates the slide portions.

As described above, the lubricating oil 305 in the inclined hole 714 is not scattered from the upper end of the eccentric shaft 711 but flows out to the upper end opening of the inclined hole 714 and the closed oil feeding passage 716.

The lubricating oil 305 flowing out of the upper end opening of the inclined hole 714 contacts an inner surface of the larger-diameter hole of the connecting section 355, which inner surface faces this upper end opening and flows out to the larger-diameter groove without being scattered. Thus, the larger-end portion of the connecting section 355 serves as the scattering suppressing section.

The lubricating oil 305 is not scattered, but flows from the inclined hole 714 into the closed oil feeding passage 716, and flows out of a lower end opening of the closed oil feeding passage 716. Therefore, the closed oil feeding passage 716 serves as the scattering suppressing section.

In accordance with the sealed compressor 300 having the above configuration, the scattering suppressing section prevents the lubricating oil 305 from being scattered. Thus, a temperature increase of the lubricating oil 305, a temperature increase of the refrigerant gas 309, and a temperature increase of the interior of the sealed container 301 can be suppressed. As a result, the volumetric efficiency of the sealed compressor 300 can be improved, and the life of the sealed compressor 300 can be extended.

The opening of the inclined hole 714 is communicated with the larger-diameter groove of the connecting section 359. This allows the lubricating oil 305 to be fed from the opening of the inclined hole 714 to the larger-diameter groove. Therefore, the lubricating oil 305 lubricates the slide portions of the larger-end portion of the connecting section 355 and of the eccentric shaft 359.

Embodiment 5

FIG. 11 is a cross-sectional view showing the sealed compressor 300.

The eccentric shaft 711 is similar to that of Embodiment 4.

The blocking wall 706 is provided in the block 347 and extends upward. The blocking wall 706 is positioned between the crankshaft 709 and the chamber 470.

If the lubricating oil 305 flows from the upper end opening of the inclined hole 714 and the closed oil feeding passage 716, toward the chamber 470, via the slide portions 437, the lubricating oil 305 is prevented from reaching the chamber 470. Or, if the lubricating oil 305 adhering onto the crankshaft 709 being rotating is scattered toward the chamber 470, the blocking wall 706 prevents the lubricating oil 305 from reaching the chamber 470. Because of this, the refrigerant gas 309 inside of the chamber 470 is not heated by the lubricating oil 305. As a result, the volumetric efficiency of the sealed compressor 300 can be improved.

In Embodiment 5, the crankshaft 709 of Embodiment 4 is used. Alternatively, in Embodiment 5, the crankshaft 343 including the scattering suppressing section 455 of Embodiment 2 and the crankshaft 343 including the scattering suppressing section 610 of Embodiment 3 may be used.

In the above described embodiments, the chamber 470 and the compression chamber 380 are separate from each other. Alternatively, the chamber 470 and the compression chamber 380 may be integral with each other.

INDUSTRIAL APPLICABILITY

A sealed compressor of the present invention is useful as a sealed compressor or the like which is capable of suppressing a reduction of its volumetric efficiency and a reduction of its life.

REFERENCE SIGNS LIST

-   -   300 sealed compressor     -   301 sealed container     -   305 lubricating oil     -   309 refrigerant gas     -   324 suction pipe     -   327 compression component     -   331 electric component     -   343 crankshaft     -   347 block     -   351 piston     -   355 connecting section (connecting rod)     -   359 eccentric shaft     -   364 main shaft     -   368 oil feeding mechanism     -   380 compression chamber     -   392 suction hole     -   395 discharge hole     -   398 valve plate     -   404 cylinder head     -   405 discharge space (discharge passage)     -   413 valve sub-plate     -   414 head separating wall     -   419 non-contact space     -   425 discharge pipe (discharge passage)     -   425 a discharge communicating pipe (discharge passage)     -   431 lateral hole (oil feeding mechanism)     -   433 penetrating passage (oil feeding mechanism)     -   434 spiral groove (oil feeding mechanism)     -   440 inclined hole (oil feeding passage)     -   452 opening hole (opening)     -   455 scattering suppressing section     -   458 sealing lid (scattering suppressing section)     -   461 small hole (scattering suppressing section)     -   464 thrust bearing mechanism     -   467 expansion space     -   470 chamber (discharge passage)     -   473 discharge pipe (discharge passage)     -   610 scattering suppressing section     -   616 guide cover (scattering suppressing section)     -   619 scattering direction changing section (scattering         suppressing section)     -   706 blocking wall (scattering suppressing section)     -   708 penetrating passage (oil feeding mechanism)     -   709 crankshaft     -   710 main shaft     -   711 eccentric shaft     -   712 lateral hole (oil feeding mechanism)     -   713 spiral groove (oil feeding mechanism)     -   714 inclined hole (oil feeding passage)     -   716 closed oil feeding passage (scattering suppressing section) 

1. A sealed compressor comprising: an electric component; a compression component actuated by the electric component; and a sealed container which accommodates the electric component and the compression component and stores lubricating oil in a bottom portion thereof; a suction pipe for guiding a refrigerant gas suctioned into and compressed by the compression component to an inner space of the sealed container; and a discharge passage for guiding the refrigerant gas compressed by the compression component, from the compression component to outside of the sealed container; wherein the compression component includes: a crankshaft including a main shaft rotated by the electric component and an eccentric shaft which is eccentric with the main shaft; an oil feeding mechanism provided in the main shaft to feed the lubricating oil stored in the bottom portion of the sealed container to slide portions of the compression component; an oil feeding passage provided in the eccentric shaft, communicated with the oil feeding mechanism and having an opening in a surface of the eccentric shaft; and a scattering suppressing section for suppressing the lubricating oil from being scattered from the opening of the oil feeding passage.
 2. The sealed compressor according to claim 1, wherein the compression component further includes: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; and a cylinder head which is fastened to one end of the block and seals one end of the compression chamber; wherein the scattering suppressing section includes a head separating wall provided integrally with the block and positioned between the cylinder head and the crankshaft.
 3. The sealed compressor according to claim 1, wherein the opening of the oil feeding passage is provided in an upper end surface of the eccentric shaft.
 4. The sealed compressor according to claim 1, wherein the scattering suppressing section includes a sealing lid for closing the opening of the oil feeding passage.
 5. The sealed compressor according to claim 4, wherein the sealing lid has a small hole.
 6. The sealed compressor according to claim 1, wherein the scattering suppressing section includes a guide cover which covers the opening of the oil feeding passage and opens at a lower end surface side of the eccentric shaft.
 7. The sealed compressor according to claim 6, wherein the compression component further includes: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; and a thrust bearing mechanism which is provided in the block and supports the crankshaft such that the crankshaft is rotatable; wherein the scattering suppressing section includes a scattering direction changing section one end of which is communicated with an opening of the guide cover and the other end of which extends toward the thrust bearing.
 8. The sealed compressor according to claim, wherein the compression component further includes: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; a connecting rod, a smaller-end portion of which is rotatably connected to the piston and a larger-end portion of which is rotatably fitted to the eccentric shaft; and a larger-diameter groove formed in an outer peripheral surface of the eccentric shaft in a fitting portion at which the eccentric shaft is fitted to the larger-end portion of the connecting rod or a surface of the larger-end portion of the connecting rod in the fitting portion at which the larger-end portion is fitted to the eccentric shaft; wherein the opening of the oil feeding passage is formed in the outer peripheral surface of the eccentric shaft, and the larger-diameter groove is communicated with the opening; and wherein the scattering suppressing section includes the larger-end portion of the connecting rod, and a closed oil feeding passage formed inside of the eccentric shaft such that the closed oil feeding passage is communicated with the oil feeding passage, one end thereof opens in a lower end surface of the eccentric shaft and the other end thereof is closed.
 9. The sealed compressor according to claim 1, further comprising: a chamber provided in a portion of the discharge passage and having an inner space defining an expansion space of the refrigerant gas compressed by the compression component.
 10. The sealed compressor according to claim 9, wherein the scattering suppressing section includes a blocking wall provided between the crankshaft and the chamber.
 11. The sealed compressor according to claim 1, wherein the compression component further includes: a block provided with a compression chamber inside thereof; a piston reciprocatable inside of the compression chamber; a valve plate provided at an end portion of the compression chamber and including a suction hole and a discharge hole; a cylinder head having a space communicated with the compression chamber via the suction hole and the discharge hole; and a valve sub-plate provided between the valve plate and the cylinder head to suppress heat from being transferred between the block and the cylinder head.
 12. The sealed compressor according to claim 11, wherein the valve sub-plate has a non-contact space in at least one of a surface at the valve plate side and a surface at the cylinder head side, the non-contact space being formed by reducing a wall thickness of the valve sub-plate.
 13. The sealed compressor according to claim 1, wherein the lubricating oil has a viscosity which is equal to or less than 8 centistokes at 40 degrees C.
 14. The sealed compressor according to claim 1, wherein the refrigerant gas includes a cooling medium containing at least one of fluorine atoms and a double bond of oxygen; and wherein the sealed compressor constitutes a closed refrigeration system.
 15. The sealed compressor according to claim 1, wherein the refrigerant gas includes a hydrocarbon-based cooling medium; and wherein the sealed compressor constitutes a refrigeration system which is limited in an amount of the refrigerant gas filled therein.
 16. The sealed compressor according to claim 1, wherein the sealed compressor constitutes a refrigeration system for heating.
 17. The sealed compressor according to claim 1, wherein the sealed compressor is used for freezing or chilling; and wherein the sealed compressor constitutes a closed refrigeration system in which a compression ratio is greater than
 10. 